Ok so I just returned from Walmart I had to go there cause I was picking up something I had shipped over there while in there I went and looked at their pitiful selection of fish and I noticed the same bettas that I've seen a few weeks ago were still there in their little rotten cups... and walmart hast the crappiest cups ever they don't even have them sealed up tightly so the water doesn't spill out. but anyway I acted on impulse and picked up one I didn't want him spending the rest of his life in there. To my surprise though he has the longest tail and he doesn't have fin clamp but i think he has a little tail rot going on now that i look closer.
Right now I got him in a small 1 gallon critter keeper without anything it it but gravel I wanted to get a bigger one but they didn't have any so I gotta order one online. He'll be ok for a few days in a 1 gallon right?
Oh and also since this one would probably won't be in a tank, how often should I be doing water changes?